1. Field of the Invention
The present invention relates to a data processing system, an apparatus and a method for processing information, a recording and playback apparatus, and a computer program for storing, playing back, and transferring a data file. In particular, the present invention relates to a data processing system, an apparatus and a method for processing information, a recording and playback apparatus, and a computer program for storing, playing back, and transferring data collected from externally connected peripheral devices.
More particularly, the present invention relates to a data processing system, an apparatus and a method for processing information, a recording and playback apparatus, and a computer program for collecting content from an externally connected data recording and playback apparatus, such as a digital camera, as one of peripheral devices and for storing, playing back, and transferring (writing back) the content. Still more particularly, the present invention relates to a data processing system, an apparatus and a method for processing information, a recording and playback apparatus, and a computer program for collecting content from an externally connected data recording and playback apparatus serving as a peripheral device and for writing back the content to the data recording and playback apparatus in a format that is reconstructable by the data recording and playback apparatus.
2. Description of the Related Art
In recent years, with the increase in capacity and reduction in size and cost of hard disk drives (HDDs), HDDs have been installed in a variety of portable devices. For example, when an HDD of several tens of gigabytes is incorporated in a digital video camera, the digital video camera can record a moving image for several to several tens of hours. Furthermore, by using random access capability of an HDD, content in a moving image and a still image can be freely edited.
For example, a digital video camera has been proposed in which a camera unit are removably connected to a recording and playback unit including an optical disk recording and playback unit, a hard disk recording and playback unit, a removable hard disk recording and playback unit, or a tape recording and playback unit. A common connection interface and a common connection mechanism between such a recording and playback unit and the camera unit are employed so that a suitable encoding recording method is selected to record and playback an image (refer to, for example, Japanese Unexamined Patent Application Publication No. 10-174032). In addition, the recording and playback unit includes an encoding/decoding circuit supporting any two or more of the Motion JPEG, MPEG1, MPEG2, MPEG4, and DV formats and a switch for switching between the formats. Thus, one camera can record and play back an image while switching between two or more encoding/decoding methods.
In general, digital video cameras using an HDD as a recording medium employ a file system, such as the FAT (file allocation table) system, and record a captured image in the form of a file.
For example, a digital video camera has been proposed that includes a hard disk based on the FAT file system as a recording processing unit and that analyzes the FAT to detect information relating to a continuity of an available area of the hard disk (refer to, for example, Japanese Unexamined Patent Application Publication No. 2006-79467). Such a digital video camera can determine whether or not the hard disk is in a state suitable for recording data using the information relating to a continuity of an available area of the hard disk detected on the basis of a FAT analysis result.
In addition, a digital video camera may be connected to a personal computer via a universal serial bus (USB) cable. In such a case, a file of a captured image is transferred from the digital video camera to the personal computer. Thereafter, a variety of data processing can be performed using a feature-rich graphical user interface operational environment provided by the personal computer. Examples of the variety of data processing include image processing, such as storage, management, playback, image quality conversion of the image file, and image editing.
For example, the digital video camera DCR-SR100 available from Sony Corporation includes a 30-Gbyte HDD and records a standard definition (SD) image in the form of a moving picture experts group 2-program stream (MPEG2-PS) file. The recorded image can be played back by the digital video camera DCR-SR100. In addition, a video stream file can be copied into an HDD incorporated in a personal computer connected to the digital video camera DCR-SR100 via a USB cable.
Most of information recording and playback apparatuses including a HDD, such as digital video cameras, are connected to a personal computer as USB slaves. That is, a personal computer serving as a USB master recognizes a digital video camera as a mass storage device, that is, one of USB hard disks externally connected to the personal computer. Thus, the personal computer can access a file using a mass-storage class. While the digital video camera is being connected to the personal computer via a USB, the digital video camera cannot provide an image recording/playback function. The digital video camera only operates as a USB slave, that is, an external HDD.
For example, a digital camera has been proposed that primarily operates as a digital camera and additionally operates as a mass storage device capable of storing a large amount of data therein when connected to a personal computer (refer to, for example, Japanese Unexamined Patent Application Publication No. 2000-307911). The digital camera generates a file in the mass storage device immediately after an image file is captured. Accordingly, the personal computer can display the generated file.
As one of use cases of a captured image, a user may write back an image retrieved from a digital video camera to a personal computer to the digital video camera. Thereafter, the user may play back and edit the image on the digital video camera. This write-back process corresponds to a process performed by the personal computer in which a stream file stored in a local disk is copied to an HDD incorporated in the digital video camera serving as a mass storage device. Since the digital video camera during USB connection operates only as a mass storage device, such a write-back process is basically performed by an authoring engine or an application tool running on the personal computer.
In most digital video cameras including an HDD dedicated to SD image capturing, the captured image is recorded in the form of an MPEG2-PS file because the image is converted to a DVD-video. In such digital video cameras, when the MPEG2-PS file is copied into a predetermined folder in the HDD incorporated in the camera from a personal computer over a USB connection, the camera can directly play back the image data. That is, a write-back operation of an image file from a personal computer to a digital video camera can be easily performed. This is also because the folder structure or the directory structure of the HDD incorporated in the camera is relatively simplified.
On the other hand, recently, the AVCHD standard has been proposed as a video camera standard for recording a high definition (HD) image. The AVCHD employs the MPEG-4 AVC/H.264 codec having a relatively high compression ratio so that an HD image can be recorded on a low-capacity and low-speed medium. Currently, the AVCHD is used for recording an HD image on a DVD disk. However, an HD image in the AVCHD format can be recorded on a variety of media, such as a memory card and an HDD.
In the AVCHD format, an HD image is recorded in the form of an MPEG2-TS file. However, not only the stream file is stored on a medium but also a plurality of management information files used for playing back or editing the moving image file are stored together with the stream file. Thus, the AVCHD format has a complicated folder structure.
Accordingly, unlike the above-described digital video camera dedicated to SD image capturing, the digital video camera supporting the AVCHD format cannot play back a written-back stream file by simply copying the stream file into a predetermined folder. That is, to re-use a stream file written back from a personal computer, not only the stream file needs to be copied into the HDD incorporated in the digital video camera, but also the management information file associated with the stream file needs to be reconstructed in a storage area of the HDD so that the structure complies with the AVCHD format. That is, an appropriate additional copy operation is needed so that the stream file complies with the AVCHD format.
More specifically, to copy a stream file from a personal computer to a digital video camera including an HDD for capturing an HD image, the stream file needs to be additionally recorded in a predetermined folder so as to comply with the AVCHD format.
However, in general, an application or an authoring engine running on a personal computer is designed so as to perform authoring on a plurality of content files at the same time (i.e., performs authoring on the basis of a predetermined folder structure complying with the AVCHD format as a unit). Accordingly, in general, the application or the authoring engine is not suitable for a method in which a stream file is added to another stream file in the AVCHD format already recorded on an internal HDD.
In addition, when a management information file associated with a stream file additionally recorded on the internal HDD is generated, the stream needs to be temporarily separated (demuxed) into moving image data and audio data and, subsequently, the moving image data and audio data need to be reintegrated together (muxed) so as to acquire a variety of parameters forming the management information. At that time, a sufficient amount of free space is required on a local disk of a personal computer in order to create temporary files.
When a stream file is additionally recorded on the internal HDD of the digital video camera after the temporary files for the stream are created on the local disk of the personal computer, the following time-consuming processes are required: (1) generating the temporary file on the local disk, (2) transferring necessary files among the temporary files to the digital video camera via a USB cable, and (3) updating the management information file on the internal HDD of the digital video camera.